Talking machine



Patented Mar. 24, 1936 uni-rap smras 7 access":

Alfred Lahr, Coteaux de Saint Gloud, France, as-

signor to Oompagnie Francaise du Mirodisque, Paris, France, a corporation of France Application December is, 1933, Serial in France February 13, 1933 It has been often proposed to rotate the disc carrying plates of talking machines not with a uniform'speed of revolution but with a uniform linear velocity of the disc with respect to the needle, so as to increase the capacity of the discs. Different solutions of this problem have been proposed. In most of these solutions use is made of the combination of a roller for actuating the disc carrying plate with a mechanism for im- 39 parting a translatory movement either to said plate, or to the roller together with the reading or tracing device.

Up to the present time, these solutions have proved unsatisfactory for practical purposes, due

to unevenness andwear and tear of the pieces in frictional contact.

This is more particularly the case when a rubher or r'ibre roller is utilized for driving a steel plate, Furthermore it is very diiiicult to provide an arrangement whereby the roller turns in exact coaxial relation to a fixed axis and the plate turns exactly in a given plane. It follows that it is practically impossible to avoid reactions which render the sound reproduction very disg5 agreeable. v

The object of the present invention is to provide a talking machine which obviates these drawbacks.

To this eiiect, according to my invention, I

36 may utilize either one or two rollers.

In the first case I make use of a hard knurled wheel or roller, for instance of steel, driven by the driving shaft (or keyed thereon), This knurled wheel or roller bears against an elastic surface.

" Owing to a suitably disposed endless screw, the rotary movement of the plate spindle causes said plate to move with a translatory displacement, while the roller and the reading (or tracm ing) device are kept stationary. or course the plate spindle might remain stationary while the reading (or tracing) device is given a translatory displacement with. respect to said spindle.

In order to disengage the parts it sufices to depress the roller; the plate can then be brought back to its initial position. It is also possible,

under these conditions, to utilize the machine with ordinary discs, the rollers being then suitably piaced and locked. f

This system makes it possible to record sounds on a disc and to subsequently reproduce them very faithfully and accurately, the-time'for which the disc can be kept going being -considerablyincreased.

In the second case, the same result is obtained by means of .two'frictlon rollers rotating with the same speed of revolution and in opposite di= rections with respect to each other, said rollers driving a plate which is held between them with a. certain force, which may be adjusted. This plate is carried on a spindle on which are mounted: Y

(a) the plate that supports the virgin or recorded disc; and,

(b) an endless screw meshing with a stationary threaded rod, which causes either the plate or the whole of the rollers to move in the direction of a radius oi the plate.

It is clear that this translatory movement'will determine the radial distance between two successive spires oi the groove in the disc, when the machine is used for recording sounds, on shall have to be equal to this distance, when the machine is used fcr reproducing sounds, whatever he the nature, the origin, or the'frequency-oi the vibrations to be recorded or reproduced.

It will be readily understood that the speed of revolution of the driving rollers must be rigourously uniform. Consequently it will be necessary to drive these rollers by means of a synchronous motor, a motor with a regulated spring, or a motor fitted with a speed governor and a fly-wheel capable of absorbing the small irregularities that may occunsuch as those due to the teeth."

The clasping of the plate between the rollers that serve to drive it will be ensured by means of screws, or springs, or in any other suitable manner.

The rollers and the plate will be made of suitable materials, according to the circumstances, for instance: steel, rubber, or any suitable plastic material. I

The friction surface of the rollers will be determined in such manner as to avoid slipping or vibrations.

In order to permit the displacement-of the movable portion (plate or rollers) and the setting back thereof into its initial position, I provide a threaded piece capable of being disengaged,

forming a nut on the threaded rod.

on the other hand, in order to obtain rotation without any radial displacement I provideeither means for disconnecting said nut or an annular" groove inthe threads of said rod at points corresponding to a predetermined speed of revolution revolutions, 33 revolutions or any other number). v

The movable system will be supported and guided, in the course of its displacement in any 55 such a'length that the plate driven by said rollers may move a distance equal to the length of its radius between said rollers.

Preferred embodiments of the present invention will be hereinafter described with reference to the accompanying drawing, given merely by' way of-example and in which:

a first embodiment of my invention;

Fig. 2 is a perspective view of another embodiment;

Fig. 2a is an elevational view corresponding to Fig. 2; s

Fig. 2b is a partial view showing a detail of Fig. 2a;-

Fig. 3 is a partial view of a modification; Fig. 4 is a partial view of still another modification.

In the embodiment shown in Fig. 1, M is a m. 1 is a diagrammatical seasons view of synchronous or regulated motor provided with a flywheel V. Said motor drives'rollers G1, G2 in opposite directions, through pinions P or any other means. S is the device for holding the shafts of rollersG1 and G: and for applying them against the plate E. Said plate is carried by'a vertical spindle A which also carries the disc D for supporting the virgin or recorded disc. The lower end H of said spindle A forms an endless screw meshing with a stationary threaded rod C in such manner as to ensure the radial displacement of system A, E, D through coupling means R, which can be disengaged at will. F1 and F1 are guiding members moving along slides so as .to ensure a rectilinear displacement of the moving system and to prevent deformation of spindle A.

Of course it should be well'understood that the arrangement disclosed by Fig. 1 is entirely diagrammatical and that it might include any details that may be useful for practical purposes but are 75 said shafts and the pitch of which should be not essential from the point of view of the present invention.

' The speed of revolution of the plate will depend on the nature of the recording or reproduction of the sounds. I a

In Fig. 2 I have shown another embodiment of y invention in which the rollers and the diaphragm or other reading device are movable, the

plate remaining stationary.

In this case, M is the motor which drives the shafts S1 and S: of pinions G1. and G2, respectively. As in the preceding example, these rollers hold between them the plate E, which is carried by spindle A on which is keyed the disc carrying disc D. Plate E may be made of reduced thickness, provided that it is capable of driving its spindle.

Rollers G1 and G1 are angularly driven by their shafts S1 and S1 but, owing to a longitudinal groove with which they are provided, they can slide along these shafts. This longitudinal displacement of the rollers along their shafts is controlled by parallel arms T1 and T1 respectively, which are carried by a shaft B which turns together with the arm 0 of the needle carrier J. Of course, arms T1 and T2 are telescopic so as to allow for the variation of distance from the rollers strain on the groove and the'needle, thesliding displacement of the rollers-along their respective shafts may be controlled by a screw parallel to equal to the radial pitch of the groove in the disc. This screw will be rotated by spindle A for instance through bevel pinions carried, respectively, by said spindle and by said screw as shown in Fi 4, or through any other means.

In order to ensure that plate E is held between rollers G1 and G1 with a constant strength, the shafts S1 and S2 of these rollers may be jointed (Fig. 3) about points 01 and O2 and subjected to the action of a spring R1 tending to press the free ends of said shafts toward plate E. The slight play that will eventually result from such an arrangement between the endless screw keyed to the driving shaft of the motor and the two pinions keyed to shaft S1 and S1 that mesh with said endless screw will not be detrimental to the precision of the transmission.

When it is desired to utilize discs adapted to turn with a uniform speed of revolution, it suflices to disconnect arm C from shaft 3 and to place and maintain rollers G1 and G1 in positions giving the desired speed of revolution of the disc (33, 40, '12 revolutions, etc.).

This shaft B may also carry a needlefor indicating the groove, so asto show thepoints at It will be understood that the combination of shaft B and of the sliding rollers permits restriction of the space occupied by the device by a distance, equal to the radius of the plate.

While I have described what I deem to be which some records should be started, this needle being mounted at any other suitable point.

eificient embodiments of my invention it should be well understood that I do not wish to be limited thereto as there might be changes made thereto, two rollers frictionally engaging said plate, one roller on each side of the plate, said rollers being disposed in symmetric relation with respect to each other as to said plate, means for imparting a uniform rotary movement to said rollers in opposite directions respectively, and

means for imparting a relative linear displace 'ment to said rollers and of said plate in a radial direction of said plate.

2. In a talking machine adapted to utilize discs, the combination of a frame, means for supporting the disc, a spindle carrying said means pivoted in said frame in a stationary position, a flexible plate keyed tosaid spindle at right angles thereto, two rollers frictionally engaging and slightly deforming said plate, one roller on each side of the plate respectively, said rollers being disposed in symmetric relation with respect to each other as to said plate, a motor, two parallel shafts driven by said motor in opposite directions slidably carrying said rollers so as to drive them angularly, and means operatively connected with said spindle for causing said rollers to slide along said shafts.

3. A talking machine according to claim 2 in which the last mentioned means comprise a shaft mounted in said frame in parallel relation with said spindle, a diaphragm carrying arm keyed to the last mentioned shaft, and two telesoopic arms adapted to be keyed to said last "mentionedshnftatoneendnndcmnectedtt transmltflnztherotuymmunentotfldmlnthe other end to-nld rollers dletosaldacrem' LAtalklnzmeehlneaciaordlngtoclelmflln 5.Ata.lklnzmech1neaeeotdlntocldm2ln which the last mentioned means comprise e which the ehattware jointed so as to be able to. screw journalled in said frame in parallel relepivot each about aflxed pdnt. andelutlc'm'eem 5, tion to said plate. a nut engaged on ma acre! for urging ma shafts toward each other. and connected to sald rollers, and means for -j' LAHR. 

